Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
  • C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D207/18—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member
  • C07D207/22—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having one double bond between ring members or between a ring member and a non-ring member with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D207/24—Oxygen or sulfur atoms
  • C07D207/26—2-Pyrrolidones
  • C07D207/263—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms
  • C07D207/267—2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom

Definitions

• the present invention relates to an improved process for the preparation of N-substituted 2-pyrrolidones (I) by the reaction of maleic acid, fumaric acid, or succinic acid or functional derivatives of these acids (compounds II) with a primary amine (III) or by the reaction of amides or imides derived from II and III under hydrogenating conditions in a synthesis stage followed by isolation, by distillation, of I and other volatile components from the resulting reaction mixture.
• the prior art includes the preparation of N-substituted 2-pyrrolidones from a large number of compounds by catalytic hydrogenation.
• the starting compounds concerned are mixtures of a primary amine (II) and maleic anhydride (DE-A 4,018,243, U.S. Pat. No. 3,109,005) or fumaric acid, maleic acid, succinic acid, functional derivatives of these acids such as succinic anhydride, or amides and imides derived from II and the acids mentioned, all of which can be hydrogenated to produce N-substituted 2-pyrrolidones. Irrespective of the nature of these starting materials the reaction mixtures obtained after hydrogenation are worked up by distillation.
• the desired pyrrolidones the more volatile pyrrolidines and the less volatile succinic imides can be separated by distillation.
• open-chained succinic amides undergo ring closure to form cyclic imides and may thus also be separated.
• high-boiling residues remain. These residues, which have hitherto been destroyed by burning, are usually equal to a few percent molar of the starting compounds; but under hydrogenation conditions, which produce the corresponding pyrrolidones with particularly high selectivity, this quantity of residuum can be considerably larger.
• the high-boiling distillation residues involved in the process of the invention are usually products which are not volatile at temperatures below 200° C. under a pressure of ca 10 mbar. These products are presumed to be oligomeric, possibly substituted, succinic diamides. These distillation residues are subjected to renewed hydrogenation.
• the hydrogenation is carried out over conventional hydrogenation catalysts, and the catalytically active component contains a Group 8-10 metal, as listed in the Periodic Table, chromium, manganese, rhenium, or copper.
• the catalysts used in the process of the invention can be either supported catalysts or solid catalysts ie, unsupported catalysts.
• Conventional support materials can be used such as activated charcoal, silicon dioxide, aluminum oxides, titanium dioxides, zirconium oxide, silicates, or zeolites.
• the catalysts are preferably activated with hydrogen prior to their use in the process of the invention.
• the active catalyst components present after calcination, generally in the form of their oxides, are reduced to a major extent, usually to the corresponding metals.
• the catalysts can be used in the form of suspension catalysts or fixed-bed catalysts.
• the reaction can be carried out in stirred autoclaves or tubular reactors. If tubular reactors are used, the starting materials can be passed over the catalyst in a packed bubble column or a trickle bed column. The reaction can be carried out continuously or batchwise.
• the hydrogen can be fed to the reaction in stoichiometric amounts but preferably in superstoichiometric amounts.
• the amount of excess hydrogen added is not crucial, since this can be recycled to the reaction.
• the hydrogenation reaction is generally carried out at temperatures ranging from 100° to 350° C. and preferably from 150° to 300° C. and in particular at from 160° to 280° C., and it is usual to operate at pressures of from 50 to 350 bar and preferably from 100 to 300 bar.
• the hydrogenation of distillation residues as proposed in the invention is generally carried out in the presence of a solvent.
• the solvent used can be virtually any solvent which is inert under the conditions of the hydrogenation, for example, water, aliphatic and aromatic hydrocarbons as well as ethers such as diethyl ether, diisopropyl ether, methyl-tert-butyl ether, dioxane, tetrahydrofuran, or mixtures of these solvents.
• ethers such as diethyl ether, diisopropyl ether, methyl-tert-butyl ether, dioxane, tetrahydrofuran, or mixtures of these solvents.
• N-substituted 2-pyrrolidones such as are produced in the reaction of the invention. Water is particularly preferred, especially for the preparation of N-methylpyrrolidone.
• Another possibility is to meter the distillation residues to the hydrogenation reactor in the form of a melt.
• the process is not subject to any discernible restrictions as regards the substituents on the nitrogen atom of the N-substituted 2-pyrrolidone.
• the starting mixtures can contain, as primary amines III, for example, aliphatic amines having from 1 to 10 and preferably from 1 to 4 carbon atoms, primary cycloaliphatic amines having from 5 to 8 carbon atoms, or alternatively primary aromatic and araliphatic amines such as aniline or benzylamine.
• the amines propylamine, butylamine, hexylamine, decylamine, cyclopentylamine, and cyclohexylamine are of prime importance, as is, in particular, methylamine.
• the hydrogenation can take place in the absence of, but preferably in the presence of, the amine used during the formation of the distillation residues. In a preferred embodiment of the process of the invention for the hydrogenation of the distillation residues, these are recycled to the synthesis stage.
• thermolysis of the distillation residues is particularly recommendable when there occurs accumulation of undesirable by-products during feedback of the distillation residues to the hydrogenation stage.
• thermolysis is generally carried out at temperatures ranging from 200° to 500° C. and preferably at from 250° to 400° C. and more preferably at from 280° to 350° C., and it is usual to operate at pressures below 1 bar and preferably at from 0.01 to 100 mbar and in particular at from 1 to 50 mbar.
• the product streams obtained by the hydrogenation of distillation residues as proposed in the present invention exhibit a comparable composition to that of the product achieved by hydrogenating the starting compounds.
• the present invention allows for the conversion of high-boiling distillation residues to N-substituted pyrrolidones in good yields.
• the N-substituted pyrrolidones and especially N-methylpyrrolidone, are mainly used as solvents and extracting agents.
• the cobalt catalyst used (prepared by the methods described in DE-A 2,321,101 and DE-A 3,904,083) had the following composition:
• the hydrogenation catalysts used in the examples were activated with hydrogen in the usual manner, prior to use.
• the hydrogenation reaction was carried out in a tubular reactor, in which 38 g of the cobalt catalyst were present in a fixed bed.
• the catalyst was used in the form of 2.5-4 mm gravel.
• N-methylpyrrolidone was 81%, 6% of N-methylpyrrolidine and 7% of succinic acid-N-methylimide also being found. The yields are based on the distillation residues, calculated as succinic acid-mono-N-methylamide.
• the hydrogenation was carried out in a manner similar to that described in Example 1.
• the catalyst used comprised 36 g of a nickel catalyst having the following composition: 50 wt % of NiO, 17 wt % of CuO, 31 wt % of ZrO 2 , and 2 wt % of MoO 3 (prepared as described in U.S. Pat. No. 5,037,793) in the form of 4 mm extrudates.
• Thermolysis 50 g of distillation residues were thermolyzed at a pressure of 1 mbar and at a temperature of 280° C. over a period of one hour. The resulting volatile products were removed by distillation and condensed. There remained as bottoms 9.5 g of residue. 24.5 g of succinic acid-N-methylimide were isolated (yield 57% based on the distillation residues, calculated as succinic acid-mono-N-methylamide), which were fed to the synthesis stage.

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• 1993
  • 1993-02-05 DE DE4303334A patent/DE4303334A1/de not_active Withdrawn
• 1994
  • 1994-01-25 ES ES94101031T patent/ES2099495T3/es not_active Expired - Lifetime
  • 1994-01-25 EP EP94101031A patent/EP0609752B1/de not_active Expired - Lifetime
  • 1994-01-25 DE DE59402263T patent/DE59402263D1/de not_active Expired - Lifetime
  • 1994-02-03 JP JP01162094A patent/JP3199946B2/ja not_active Expired - Fee Related
  • 1994-02-04 US US08/191,649 patent/US5434273A/en not_active Expired - Lifetime

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